Do the breaker amp readings sum up to dictate my current panels total / possible amperage?

Question

So I know practically nothing about houses having rented for many years, just bought a house and was told by my inspector the panel is only a 70 amp panel and will need to be upgraded before I go to install AC.

I took him at his word, and had one AC consult, mentioning this to the guy he looked at my panel and agreed it needed an upgrade.

He gave a terrible quote ($5500 for a 3 ton goodman AC install without the electrical work, no ducting work necessary), so I got somebody else to give me a quote.

Now here's the problem: Fellow comes over and says I have a 150 amp panel and there's room (which I can see) for a couple more breakers on it, and gives me a considerably better AC quote (3500 for a lennox 3 ton 14 seer, all the same bells and whistles).

So now I'm thinking, considering how terrible the quote was from the first consult, perhaps he was just trying to squeeze even more money out of me? Why did my inspector tell me it was a 70 amp panel?

I look at the panel and there's like 6 or 8 15/20 amp breakers on it as well as a 30 amp double-breaker thingy (not sure if this is 30 per or 30 total) and a 50 amp double-breaker thingy.

I'll get a picture when I get home to post here, but off hand my question is:

Is it accurate to say I definitely have over a 70 amp panel due to the sum of amps on breakers in there right now? Is the sum of those little labels on the breakers make up my panels current amperage?

I look online for 70 amp panel and it's this tiny dinky thing with 3 breakers on it..

Edit: Here are the pictures, if this is not a 70 amp can anybody identify the amps?

Appearances to me are the diagram on the box does not match the actual panel, as the panel has 20 breaker spots (as I read it) while the diagram shows 14. And yes, I realize it's missing a main breaker, so I included the other two pieces I understand identify the max amp load; the conduit and the meter.

Answer 1

I've labeled your photo, which might help you understand what's going on.

The Panel Rating

The panel is rated to support 125 amperes, when connected to a 120/240 volt 3 wire system. This means that 125 amperes can flow through each of the upper bus bars and each main lug, without anything melting or catching fire.

The Upper Section

The top two double pole breakers are before the "main" disconnect, which means they will always have power when the wires feeding the panel have power. I'm guessing there is a disconnect ahead of this panel, maybe at the meter or as a standalone disconnect. Based on their size, I'm guessing one (50A) is for an electric stove, electric heater, or maybe a subpanel. The other (30A) is likely for a dryer, water heater, subpanel, or some other appliance.

The Lower Section

The next double pole breaker (50A) controls the flow of electricity to the lower section of the panel. Unlike the double pole breakers above, this one should not have any terminals where wires can connect. The lower section is rated for a maximum of 100 amperes, so the breaker protecting it must be 100 amp or less (50A in your case).

Branch Circuit Section

The lower section (highlighted in purple) is where the branch circuit breakers connect, and has a maximum breaker size of 70 amperes. This means the largest breaker that can be connected in this section, is a 70A breaker.

Upgrade Required?

Since there is only a single available slot (3), it's not likely a central A/C system could be connected without moving things around (at the very least). Upgrading the panel might be your only option, but it would depend on the existence (or lack thereof) of a sub panel, and the existing service provided to the building (and availability of services in the area).

A subpanel may be an option, however, it would require more information than you have provided here.

Depending on the service provided to the building, upgrading the panel may include an upgrade to the service. Installing a new 125A panel is useless, if you don't also have the service upgraded to support 125 amperes.

To determine if an upgrade is required, contact a local licensed Electrician to do a load calculation on the building.

Breakers Protect Downstream Wiring

Short-circuit and/or overcurrent protection devices (breakers, fuses, etc.), are designed to protect the wiring downstream (after them in the circuit). For example. If your panel did have a main breaker, it would be sized to protect the panel wiring. The breaker would not be sized to protect the wiring feeding the panel or anything before the breaker, only the wiring after the breaker.

Summing Up Breaker Ratings Means Nothing

If you total up the rating of the breakers in the branch circuit sub-section, you'll find that you have 85A on leg A, and 105A on leg B. Which means... Well, absolutely nothing. The only limitations here are that there can only be as many breakers as will physically fit, and no one breaker can be larger than 70A.

If more than 15 amperes flow through the breaker in slot 4 , that breaker will trip (open). This protects the wiring connected to that breaker. If more than 50 amperes flow through any combination of breakers on either leg A or B in the branch circuit sub-section, the sub- section breaker will trip (open). This protects the wiring between the sub-section breaker, and the branch circuit breakers.

You could theoretically. have breakers totaling 1,000,000A. It still wouldn't matter, as long as you have proper overcurrent protection.

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_{If I've missed anything, or haven't explained something properly. Feel free to ask additional questions, or point out mistakes in the comments below.}

Answer 2

No, just because there are X amps of breakers in the panel does not mean the panel is X or any specific size panel. Indeed, in many services the sum of the breakers is more than the panel size simply because it is known that not everything is "on" at once. For example, electric heating and air conditioning are not usually operated simultaneously.

The panel capacity is determined by how much current it can safely carry through its bus bars. The panel must be sized not to exceed the utility meter nor the utility feed.

If the panel does not have a main breaker—which is usually the panel's rating—then you might have to open it up and look at the manufacturer's label.

By the way, the 30 amp double breaker is simply two 30 amp breakers mechanically tied together so that if either trips, they are both shut off. Same for the 50 double. It switches 100 amps, 50 on each leg. (I am assuming the double breaker looks similar to this:

Answer 3

The circuit breaker is rated at 125 A, according to its label. It is a "split-bus" panel. It is currently configured to have three "main" breakers (that is, you have to flip three things to turn off your electricity) which are wired in parallel. Counting the used power is a little bit tricky since you must perform the count for each leg individually: You may have up to 125 A on L1 and another 125 A on L2. I count 130 A on each: 50A + 50A + 30 A double pole breakers.

So, your installation is currently not in compliance with its design specifications (by 5 A on each line). You should reduce the current rating of one of these three breakers by at least 5 A.

For the bottom sections (individual breakers), you have 105 A of breakers on one leg and 85 on the other. You may want to swap some of these to better share the load between the two legs. It is acceptable that this count be above the 125 A because its total current draw is being limited by the 50 A breaker that you have installed. To repeat, even though the bottom breakers add up to a very large current, the 50 A breaker (2nd down on the left) will limit the total current of the single pole breakers to a total of 50 A.

In addition, I don't know what size conductor your service uses. You may want to verify that the conductor is sufficiently large for a 125 A load.

If you do not have a large house and you mostly have non-electric appliances (such as natural gas), then 125 A is plenty. But, it looks like you do not currently have enough free spaces in the breaker panel for a new two-pole breaker for the A/C.

Answer 4

I concur this is a 125A panel, with a limit of 70A per branch circuit (breaker) except for the mystery breaker, which can be 100A.

Once upon a time there was a "Rule of Six", which said you must be able to shut off all power by throwing no more than six breakers. Yours is indeed a "Rule of Six" panel but with three: the 2-pole breakers in positions 1, 2, and the (unnumbered) mystery position below 1.

It's very typical for a "Rule of Six" panel to use one of its six breakers (3 in this case) to power a "built-in subpanel" intended for smaller loads. That is what the mystery breaker does. Half-spaces #3 through #14 are the "subpanel". Together they cannot exceed whatever the mystery breaker's amp rating is, 50A I gather.

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There is one code violation and several "urgent upgrades" called for.

Code requires you to obey all instructions and labeling (NEC 110.3). Your labeling plainly says position 1 can only be a 2-pole breaker that is full size, e.g. GE's THQL series, which note the panel label, is an authorized breaker type. What's in there is a THQP, GE's unique format of "double-stuff" 2-pole breaker where it straddles two spaces. This is a Code violation and you need to spend $9 on the correct full-size breaker. Since double-stuff breakers are not allowed here, I can only guess your panel cover doesn't have breakaways for them and you have a 1/2" gap above and blow that wrong breaker. Super not cool. Panels should never have open-space gaps.

Now I also am looking at the neutral bar and I see at least 6 neutral wires on small branch circuits where the wire is aluminum. Now aluminum is fine for the big feeders like your supply cable, because those tend to be installed with care. But for 15-20-30A branch circuits, aluminum requires very precise technique and properly rated terminations - and in the 1960s-80s, it didn't get it. Installers worked hastily and shabbily, and the industry didn't know about correct torque, No-Ox compound, Alumiconn splices, or CO-ALR terminations as they do now.

"OMG rewire my whole house" -- no. The usual failure mode of aluminum wire is series arcing. You can get special breakers called AFCI that detect and trip on series arcing. Put an AFCI on every aluminum circuit, and then sleep well. At your leisure you can retrofit CO-ALR rated receptacles, Alumiconn splices etc.

The problem is all your "subpanel" breakers are double-stuffs, and AFCI breakers don't come in double-stuffs. The functionality will not fit in a double-stuff.

Nor is there room in this panel to replace six double-stuff breakers with full-size breakers.

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So my recommendation is a subpanel. The labeling says the largest branch circuit breaker you can use is 70A, so OK. Fit a 70A breaker in whichever position you can spare, either 1, 2, 3-4-5-6, (or 4-5 if you can find a double-stuff THQP270). Feed that over to a new subpanel. You are welcome to use another GE Qline panel if you prefer.

Then, reroute as many branch circuits as you can from spaces 3-14 to the new subpanel. I would aim for a subpanel location that let the old aluminum wiring reach the new subpanel without adding another splice to extend the aluminum wire. The copper circuits, feel free to splice them - no more than 2 circuits in a 4x4x1.5 box, no more than 4 circuits in a 4-11/16 square deep box.

Despite having many more breaker spaces, your house will still use the same energy as before, because you'll still turn the same stuff on.

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Lastly instead of A/C, consider a heat pump or "mini-split". These are air conditioners, but are reversible - in cold weather they can chill the outdoors and blow the hot air inside your house, heating at well over 100% thermal efficiency, so you spend 1 watt to move 3-4 watts of heat into your house (or more depending on outside temp and SEER rating).

Answer 5

I just worked on a G.E Load Center of this type. Yes, it's old! Unfortunately, I had to adopt the existing Load Center, but I replaced all the OPDC's. So, I made it a little safer.

To my understanding of this type of Panel: (1)The Max Amperage is 125. Done!

(2)The Max OCPD is 70 amps on any Branch Terminals.

(3)The Main Breaker for the Lower Branch Terminals is rated for maximum of 100 amps.

note: These G.E. Breakers have clips on the top & bottom to secure to the terminal and fixed bar. The G.E. push-ins are not compadable with this type of Load Center. Also, keep in mind, that adding all the OCPD's does not determine the total Amperage Load, but that the Dwelling Unit has been calculated accordingly. So, that being said, it is a Calculated Load.

Fortunately, these breakers were available at Home Depot.

Answer 6

In your first photo, under the section entitled "MAIN RATINGS", it clearly states: 125 AMPERE. That is the maximum capacity of your load panel. In most houses, the sum of the ratings of all of the circuit breakers will exceed this number. That is because it is assumed that not all of the loads will be on simultaneously. Above that section, under the "TYPICAL WIRING DIAGRAM", it states that there can be a maximum of 22 circuit breaker poles and that no circuit breaker can exceed 70 amperes. The latter may be the source of the 70 amp limit that your electrican mentioned. That said, 125 amperes is too small if you are going to add central air conditioning. Also, you should have a primary breaker equal to the capacity of your system so that if that capacity is exceeded (without exceeding any single branch breaker), the house will be protected.

Answer 7

According to the panel label, it is a 125A rated panel with a 100A sub-section. The complete panel is rated at 125A, the sub-section is rated for 100A. The maximum breaker anywhere in the panel can be a 70A. (unless it has

The comment that starts off "The circuit breaker is rated at 125 A, according to its label. It is a "split-bus" panel"....... doesn't know exactly what he's about.... nor does the comment starting out, "In your first photo, under the section entitled "MAIN RATINGS"".....

To figure out the current load on the panel, you must find out what your loads are, for instance just because you have a 20A breaker, your load is typically anywhere between a fraction of an amp (a low wattage) to 16 amps (1920w) (80% of 20A breaker rating). A dryer for instance, on the 30 amp breaker, is typically 5000 watts, which is 20.8333 watts, you must oversize the breaker for motors. You can connect more load to your panel than it is rated for, because of diversity (not all are on at once). if you overload it, the main breaker will trip. To figure out what you can put on your panel, you can perform a calculation per the NEC. This aims a bit low, so you could monitor it for a period of time if you wanted to, to determine how much more capacity you have..

If you were to turn everything on at once, your load cannot exceed 30,000 watts (30kw). if a load is on for more than 3 hours you must size the breaker for 80% of the continuous load. so if this panel were to only serve lighting, heating, or cooling your max draw could only be 24,000 watts (24kw) (100A)

125 Amps x 240 olts = 30,000 Watts

Answer 8

This must be a really old box because I see a 50 amp breaker and a 30 amp breaker I d and main breaker on the top and main breaker on the top. This box must be a from the late from the late sixties. or early seventies but since you're changing the box you'd be better off with a square D. 200 amp box just found this post Taylor I respond to it like a nation is in the bottom. You only have a 50 in a 30 which makes Makes a total of 80 amps